Answer:
a mutation that blocks the GTPase activity of Ras
Explanation:
A G protein in inactive state is GDP bound but as soon as a guanine exchange factor (GEF) exchanges it with GTP it gets activated which means that in GTP bound state it is active. G - protein has endogenous GTPase activity. Upon interaction of GAP, the GTPase activity of this protein is exhibited. When GAP is present, hydrolysis of GTP into GDP occurs which leads to inactivation of G protein. A mutation which will block GTPase activity of Ras will therefore result in constitutive active signaling even in the absence of ligand binding to it's receptor. In such scenario, GTP will not be hydrolyzed into GDP so signaling will be up-regulated.
Answer:
A cinder cone is a short, steep volcano that blasts out
pyroclastic material.
Explanation:
A cinder cone is basically a sharp conical hill which consist of a loose pyroclastic fragments that are being formed on the sides on volcanic vent.
Simply think of a steep volcano and how it acts when it blats out, this is what cinder cone is. When the lava is blown out in a very violent manner, it breaks in to very small particles that can be addressed as cinder. Almost all the cinder cones are made up of pyroclastic substance.
Answer:
Example of the Epistasis in plants is observed in the "summer squash".
Explanation:
Epistasis refers to a gene interaction in which one gene is masked by the other gene and affect the phenotype. The gene which masks the other gene is known as the epistatic gene and the gene which is being masked is known as the hypostatic gene.
The epistasis gene effect is observed in which more than one gene controls the same phenotype.
The example can be observed in the summer squash fruits in which more than one gene controls the color of the fruit.
The summer squash can be controlled by the white allele (W), Yellow allele (G) and the green by the recessive form of the w and g. If the W gene is present than it masks the other allele and thus white colour becomes dominant and is considered the case of the dominant epistasis.
Nucleotides are the subnit that is polymerized (associated into a long chain) to make nucleic acids. (DNA and RNA) Nucleotides comprise of three littler parts: a ribose sugar, a nitrogenous base, and phosphate base.
Answer:
<h3>A. </h3>
Explanation:
<h3>Tutorial</h3><h3>Diffusion</h3><h3>Diffusion means that the net movement </h3><h3>of particles (molecules) is from an area of high concentration to low concentration.</h3>
<h3>Graph of the simple and facilitated diffusion taking into account the rate of uptake and the concentration</h3>
<h3>If the particles can move through the lipid bilayer by simple diffusion, then there is</h3><h3> no limit to the number that can fit </h3><h3>through the membrane. The rate of diffusion increases linearly as we add </h3><h3>more particles to one side of the membrane.</h3>
<h3>If the particles can only pass through protein channels, then the rate of </h3><h3>diffusion is determined by the number of channels as well as the number of particles.</h3>
<h3>Once the channels operate at their maximal rate, a further increase in </h3><h3>particle numbers no longer increases the apparent rate of diffusion. At this limited rate we describe the protein channel as being saturated.</h3>
<h3>The cartoon illustrates several points about facilitated diffusion. The particles are more concentrated on one side of the membrane, and yet they can move in both directions. However, the net movement is from high particle concentration to low. If the number of particles gets so high on one side of the membrane that they</h3><h3> interfere with diffusion through the </h3><h3>protein channel, then we observe a limit to the rate of diffusion at the point of saturation.</h3>
<h3>Illustration of facilitated diffusion</h3><h3>animation used with permission of the Virtual Cell Web Page</h3><h3>Problem 7 | Answer | Problem 8</h3><h3>The Biology Project > Cell Biology > Cell Membranes > Problem Set</h3>
<h3>The Biology Project</h3><h3>Department of Biochemistry and Molecular Biophysics</h3><h3>University of Arizona</h3><h3>May 2002</h3><h3>Revised: August 2004</h3><h3>Contact the Development Team</h3>
<h3>Simple diffusion does not require energy: facilitated diffusion requires a source of ATP. Simple diffusion can only move material in the direction of a </h3><h3>concentration gradient; facilitated </h3><h3>diffusion moves materials with and against a concertion gradient. </h3>
